~ an enthusiastic meddler exploring photography

More manual focus …

I guess I touched on this in the previous post, but I’m sure there are plenty of people wondering why I would persevere with trying to get manual focus lenses to work on my modern digital camera, when a modern auto-focus 50/1.8 would cost maybe 50 quid and be guaranteed to work.

Well admittedly fifty quid is not a lot when to comes to photo gear, but it’s fifty quid more than nothing, which is how much the lenses I already own cost. And of all the features of a lens, auto-focus is probably the least important to me. In an action shooting situation I would miss it perhaps, but that’s not really my oeuvre. The important thing to me is the optics and in that regard there’s really nothing very significant that has changed between a lens from the 60s to a modern equivalent. Although you ‘ll probably find the build quality better on the old ones – much less plastic used. Also without the need for motors and/or gears to drive the auto-focus manual lenses are generally smaller if not always lighter. On the other hand coatings have improved making modern lenses less susceptible to flare and internal reflection.

Another reason is that the nifty-fifty might be cheap, but on my crop-sensor 20D it’s too long – I was after a true “normal”, something around the 30mm mark, and the 28mm f/2.8 I had knocking about seemed like it would do for a start. As we saw previously it didn’t really work out, but that’s not the end of the manual focus story.

If I can return to talking about registers – the FD adapter shows that if you’re trying to use a lens with a shorter register than your camera, you need to modify the lens, or introduce extra optics. If, however, you’re trying to use a lens with a longer register than your camera, you are in a much better situation. All you need is an adapter of the correct thickness and you can place the lens at the exact distance from the sensor it was designed to be. For a Canon owner this is very useful. As this list of camera system register distances shows the EOS register is smaller than quite a lot of other systems, notably Pentax K, M42, Olympus OM, and the venerable Nikon F. This means that for just a couple of quid you can get a simple adapter for these lens mounts and put any of hundreds of lenses on your EOS body with proper infinity focus.

I did just that with a Pentax 50mm f/1.7 I acquired for the bargain price of £0.00 and I have to say it worked beautifully. However, it did confirm to me that 50mm is too long on a crop body so I still needed an alternative. Eventually I stumbled on a real beauty – a Nikkor 35mm f/1.4 Ai for about half the price of a new AF Sigma 30mm f/1.4. It looks a little odd mounted on the 20D and all that glass is a tad heavy, but it works a treat. As a bonus I can also use it on my A-1 film camera.

At 35mm it’s a shade longer than a true normal for the 20D’s APS-C sensor and is just the right focal length for general shooting and at f/1.4 it’s more than happy in low light. There’s something about the way it renders colour that is just gorgeous but that I can’t really quantify, and at f/8 it is wicked sharp.

Of course, all this manual stuff has its issues. Manual focus is generally slower than a modern AF lens, and modern viewfinders generally aren’t designed with it in mind. On a crop sensor body the viewfinder is correspondingly smaller and darker than a film or full frame camera, and the focusing screens aren’t designed with precise manual focus in mind. Of course in other ways it can be useful. For example, if you’re focusing on an object away from an AF point, you don’t have to worry about focus lock and shifting the plane of focus as you recompose, you simply focus.

As well as focus, aperture is naturally manual too. Since I usually shoot in aperture priority or manual anyway this isn’t an issue. TTL metering generally works well I just have to remember to close down the aperture after focusing, before metering and taking a shot. In fact I’m so pleased with the Nikkor that I sold my general purpose 17-85mm zoom. With the overlap from other lenses at the wide and tele ends of the range and the Nikkor in the middle, it just wasn’t getting used. I’m not suggesting this manual focus lark is for everyone, but for me it’s a cheap way to get some great optics on my camera, and it works for me.